- Asymmetric Synthesis of Chiral Bicyclo[2.2.1]hepta-2,5-diene Ligands through Rhodium-Catalyzed Asymmetric Arylative Bis-cyclization of a 1,6-Enyne
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A series of novel chiral diene ligands (1R,4S)-L1, which are based on the bicyclo[2.2.1]heptadiene skeleton and are substituted with methyl and an ester group at the bridgehead carbons, were synthesized through rhodium-catalyzed asymmetric arylative bis-c
- Chen, Chen,Hayashi, Tamio,Meng, He,Ming, Jialin,Sun, Chao,Wei, Haili
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supporting information
p. 6311 - 6315
(2021/09/02)
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- Chiral N-aryl tert-butanesulfinamide-olefin ligands for rhodium-catalyzed asymmetric 1,4-addition of aryl boronic acids to cyclic enones
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Chiral N-aryl sulfinamide-olefins which are readily synthesized via C-N coupling and nucleophilic substitution have been used as chiral ligands, which demonstrate moderate to excellent asymmetric catalytic performance in the rhodium-catalyzed asymmetric 1
- Yuan, Shuai,Zeng, Qingle,Wang, Jiajun,Zhou, Lihong
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supporting information
p. 32 - 42
(2021/02/09)
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- Fine-Tuning the Bicyclo[3.3.1]nona-2,6-diene Ligands: Second Generation 4,8-Substituted Dienes for Rh-Catalyzed Asymmetric 1,4-Addition Reactions
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Design and synthesis of the second generation C2-symmetric 4,8-endo,endo-bis(alkoxy) bicyclo[3.3.1]nona-2,6-diene ligands possessing additional 4,8-exo,exo substituents is reported. The 4,8-exo,exo groups provide a further element for fine-tuning of the ligand structure by enforcing conformational rigidity of the 4,8-endo,endo side chains. Such tetrasubstituted bicyclo[3.3.1]nona-2,6-dienes were employed as steering ligands in the rhodium-catalyzed arylation of cyclic enones with arylboronic acids, providing the corresponding 1,4-addition products in good to excellent yields (69–99 %) and enantioselectivities up to 99 % ee.
- Bieliūnas, Vidmantas,Ston?ius, Sigitas
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p. 3815 - 3823
(2021/07/28)
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- Control of Enantioselectivity in Rhodium(I) Catalysis by Planar Chiral Dibenzo[a,e]cyclooctatetraenes
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Planar chiral 5,11-disubstiuted dibenzo[a,e]cyclo-octatetraenes (dbCOTs) have been developed as the first useful chiral homologs to dbCOT-ligands for asymmetric applications. Methods enabling the preparation of such compounds on a gram-scale in enantiomerically pure form are described. Evaluated as ligands in rhodium(I)-catalyzed 1,4- and 1,2-arylation reactions, tertiary and quarternary stereogenic centers were formed with excellent yields and selectivities of up to >99 % ee. A catalytic asymmetric synthesis of a key cyclization precursor to (?)-penifulvin A highlights the system in an applied context.
- Melcher, Michaela-Christina,Iv?i?, Trpimir,Olagnon, Charlotte,Tenten, Christina,Lützen, Arne,Strand, Daniel
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supporting information
p. 2344 - 2348
(2017/12/26)
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- Chiral Phosphorus-Olefin Ligands for the RhI-Catalyzed Asymmetric Addition of Aryl Boronic Acids to Electron-Deficient Olefins
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New chiral phosphorus-olefin hybrid ligands derived from the rigid "privileged" l-proline have been conveniently prepared and applied in the rhodium-catalyzed asymmetric arylation of electron-deficient olefins with arylboronic acids at room temperature; t
- Chen, Qian,Li, Liang,Zhou, Guangli,Ma, Xiaoli,Zhang, Lu,Guo, Fang,Luo, Yi,Xia, Wujiong
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supporting information
p. 1518 - 1522
(2016/06/01)
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- A New Type of Chiral Cyclic Sulfinamide–Olefin Ligands for Rhodium-Catalyzed Asymmetric Addition
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A new type of chiral cyclic sulfinamide–olefin ligands, N-allylic 2,3-dihydro-1,2-benzoisothiazole 1-oxides, with 2,3-dihydro-1,2-benzoisothiazole 1-oxide as a unique chiral skeleton, is developed for the highly enantioselective rhodium-catalyzed asymmetr
- Wen, Quan,Zhang, Li,Xiong, Jing,Zeng, Qingle
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supporting information
p. 5360 - 5364
(2016/11/22)
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- Convenient in situ generation of a chiral bis-N-heterocyclic carbene palladium catalyst and its application in enantioselective synthesis
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To simplify catalytic reactions employing chelating bisNHC-metal complexes, studies were conducted to elucidate conditions for the in situ generation of a chiral chelating bisNHC-palladium catalyst from the corresponding diimidazolium salt. The method provides a convenient entry to catalytic reactions and eliminates catalyst preparation steps. In addition to the in situ prepared catalyst, for comparative purposes, isolable species were synthesized and characterized by NMR spectroscopy, combustion analysis, and single-crystal X-ray diffraction. Employing C2-symmetric ligands derived from trans-9,10-Dihydro-9,10-EthanoAnthracene-11,12-diyl (DEA) and trans-9,10-Dihydro-9,10-EthanoAnthracene-11,12-diylMethanediyl (DEAM), diNHC-Pd complexes were synthesized and tested for activity in enantioselective arylboronic acid addition to cyclic enones.
- Mullick, Amrita B.,Jeletic, Matthew S.,Powers, Andrew R.,Ghiviriga, Ion,Abboud, Khalil A.,Veige, Adam S.
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p. 810 - 819
(2013/07/05)
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- Synthesis of enantiomerically pure P-stereogenic diphosphacrowns and their palladium complexes
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A practical synthetic route for enantiomerically pure P-stereogenic diphosphacrowns was developed by using a P-stereogenic bisphosphine as a chiral building block. Their molecular structures were confirmed by NMR spectroscopy and X-ray crystallography. Complexation of the diphosphacrowns with palladium was carried out, and the corresponding palladium complexes were obtained. The P-stereogenic diphosphacrowns were applicable to the chiral ligand for the asymmetric 1,4-addition of arylboronic acids to α,β-unsaturated ketone catalyzed by palladium. This reaction proceeded smoothly to afford the corresponding 1,4-addition products in high yield with good enantioselectivities.
- Morisaki, Yasuhiro,Imoto, Hiroaki,Hirano, Koji,Hayashi, Tamio,Chujo, Yoshiki
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supporting information; experimental part
p. 1795 - 1803
(2011/06/17)
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- Monodentate non-C2-symmetric chiral N-heterocyclic carbene complexes for enantioselective synthesis. Cu-catalyzed conjugate additions of aryl- and alkenylsilylfluorides to cyclic enones
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(Chemical Equation Presented) A new class of enantioselective conjugate addition (ECA) reactions that involve aryl- or alkenylsilyl fluoride reagents and are catalyzed by chiral non-C2-symmetric Cu-based N-heterocyclic carbene (NHC) complexes a
- Lee, Kang-Sang,Hoveyda, Amir H.
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body text
p. 4455 - 4462
(2009/09/30)
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